Some PC processors and hardware configurations aren’t supported by Technical Preview, including a small number of older, 64-bit CPUs, and some 32 GB and all 16 GB devices running a compressed operating system.
To access the Windows Store and to download and run apps, you need an Internet connection, a screen resolution of at least 1024 x 768, and a Microsoft account.
The Windows Store in Technical Preview will have many (but not all) Windows 8.1 apps available. (Apps for Windows 10 Technical Preview will not be available for PCs running Windows 8.1 or Windows 8.) Keep in mind that if you install the preview but then decide to go back to Windows 8.1 or Windows 8, you might have to reinstall your apps from Windows Store.
After you install the preview, you won’t be able to play DVDs using Windows Media Player.
If you’re running Windows 8.1 but haven’t installed Windows 8.1 Update yet, you won’t be able to install Technical Preview. Try running Windows Update to get Windows 8.1 Update before you install Technical Preview, or you can download an ISO file instead.
If you have Windows 8 Pro with Media Center and you install the preview, Windows Media Center will be removed.
The preview won’t work on Windows RT 8.1 editions.
Family Safety is not included with Technical Preview.
There is no N edition of Technical Preview, so if you upgrade to Technical Preview from an N edition of Windows, you will no longer be running an N edition.
If you’re running Windows 7 without SP1, you can only upgrade to the preview by downloading an ISO file. If you install Windows 7 SP1, you can upgrade to the preview by using Windows Update or by downloading an ISO file.